Clamp for master sheets of printing machines



May 22, 1951 E. J. JANKE 2,553,856

CLAMP FOR MASTER SHEETS 0F PRINTING MACHINES Filed March 1, 1946 3 Sheets-Sheet 1 INENTOR. BY j 2145 [fem 9%@ m May 22, 1951 E. J. JANKE CLAMP FOR MASTER SHEETS 0F PRINTING MACHINES s sheets-sheet 2 Filed March 1. 1946 INVENTOR wf L @d We/ecual l May 22, 1951 E, J, JANKE 2,553,856

CLAMP FOR MASTER SHEETS 0F' PRINTING MACHINES INVESTOR.

WW1/V BY @ff/bl, @dig/777i Patented yMay 22, 1951 CLAMP FOR MASTER SHEETS OF PRINTING MACHINES Edward J. Janke, Cleveland, Ohio, assigner to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Application March 1, 1946, Serial No. 651,081v

a claims. (o1. T01-415.1)

1 The object of this invention is to provide em cient means on the master drum of a printing machine to enable it to hold interchangeably masf ter sheets having different formation at their clamped ends.

In oice printing machines operating on the planographic or master-sheet principle itis very desirable to employVA master sheets of different characteristics for different uses, for instance, for short runs a comparatively thin paper master having a suitable treated surface may be used; for longer runs a thicker paper master sheet; and for still longer runs a metallic sheet. It has been found most satisfactory to make the-thin paper sheets straight across at their ends and irnperforate; to make the metallic sheets with scalloped ends, each ear carrying a perforation, while the heavier paper sheets are sometimes made Iwith straight ends and sometimes with a row of perforations behind such straight end.V

`It is an object of my invention to provide clamping means for the leading and trailing ends of the sheet adapted to hold all of these forms of master sheets.

While the leading end ofthe sheet may be clamped in fixed position, there is more diiculty with the-trailing end clamp,` .as it should be movable inwardly to apply tension to the sheet, and the present invention is especially concerned With provision on the tensioned trailing end clamp for clamping means to coact with the differently formed master sheets.

My invention is illustrated in the drawings hereof and'is hereinafter more fully explained and the essential novel features are set out in the claims. Y

In the drawings, Fig. l is a plan partly broken away of a printing drumv equipped with my clamping means, the view showing a master sheet on the drum partly broken away t disclose parts beneath it; Fig. 2 is a plan of an interchangeable pin bar used on the trailing end clamp;

Fig. 3 is a sectional end elevation, cross-sectioned through the drum, as indicated by the line 3-3 on Fig. 1; Fig. 4 is a fragmentary view of a portion of the drum and the trailing lend clamp open ready to receive a master sheet, this View being taken, for instance, in a plane indicated by the line 4--4 on Fig. 1; Figs. 5, 6 and 'lare cross sections on .a larger scale through different portions of the trailing end clamp, as indicated by the correspondingly numbered lines on Fig. 1; Fig. 8.is a sectional view of the parts as shown in Fig. 7 in the act of being separated; Fig. 9 isa plan of a portion of the vprintingdruln with 2 a scalloped perforated master sheet mounted thereon; Fig. 10 is a fragmentary plan of a pin bar forming a portion of the trailing end clamp when set for scalloped and perforated sheet shown in Fig. 9.

`In Figs. 1, 3, 4 and 9, I0 indicates a suitable drum adapted to be embraced by a master Vsheet for the most of the circumference but having an arcuate gap in which is mounted clamps for the leading end and trailing end of the sheet. In

Figs. l and 3, I have shown a normally imperforate thin master sheet A on the'drumand in Fig. 9 a perforated scalloped-end sheet B on the drum.l l Y -f Referring rst to the leading endclamp, shown in Figs. l and 3, this comprises a longitudinal bar 20, pivotally carried and adapted to coact-With an anvil in the form of a flanged' bar 22 mountedV on the end Il of the drum shell .at the gap.v I provide a special form of continuous hinge 24, which has one leaf extending between the anvil and the end of the drum shell. Screws 25 passing through the anvil and this leaf andl threaded inthe drum shell hold these parts rigidly in position. The free leaf 26- of the hinge is secured by screws or otherwise to the back of the'bar 20. v

To enable springs to act on the bar 20, tending to-seat it, I bend inwardly end portions-21 of the leaf 26 of the spring, as shown in Figs. 1 and 3; 1 and I attach to these inwardly projecting arms tension springs 10, the other ends of which Yar suitably anchored. Y Y The Outer ange 2| ofthe anvil 22 is preferv ably continuous to provide a straight edge over which the master sheet may make lan abrupt U-turn, as shown in Fig.r 2. The flange 23 at the inner end of the anvil is for the purpose of pro v viding a stop to engage--the end of the master sheet and enable it to be accurately positioned, If desired, this -very quickly, upon insertion. flange may be discontinuous; that is, in the form of two or more tongues'registering `with receiving notches in the bar20.

The outer surface of the clamping lbar 20 is -cut off at an angle, as shown in Fig. 3, and

mounted on this surface is a bar 28 provided with outwardly and backwardly projecting spaced hooks 29. The inner face of the bar 20, in coaction with the anvil is adapted to kink the endV of a thin or imperforate master sheet extending at each end, each provided with a slot b through which the hooks 29 may readily extend.

The trailing end clamp, which is adjustable to coact with either an imperforate or perforate master sheet, will now be described.

The shell of the drum l is formed at its end opposite the leading end clamp with a flat inwardly extending surface |2 to which I secure, by screws or otherwise, a bent plate, the inwardly projecting free portion of which is slotted to pro= vide a series of teeth 30, which form the anvil for the movable clamping member, while the attached part 3| may be continuous and secured by screws to the drum shell.

The clamping member to Vcoact with the anvil 30 comprises a longitudinal bar 40, the ends of which are bent downwardly to provide two arms 42, each of which is longitudinally slotted at 43.

Extending through the slots are pins `42| pivot-V ally attaching the bar to the drum. Tension springs actingon the bar tend to pull the cla-mping member inwardly and downwardly toward the'anvil 3|). For convenience, I prefer to utilize as these springs the vsame springs i0 which operate to seat the leading end clamp, each clamp thus forming the spring anchorage for the other Clamp The member on the trailing end clamp which engages the master sheet comprises a pin bar exten-ding along and secured to the bar 40. I provide a plurality of these pin bars interchangeably mounted on the bar 40 and carrying differently spaced pins; thus as s hown in Figs. l to 8, I have provided a pin bar 5U carrying a row of relatively close pins 5|.

The pin bar is removably mounted on the under side of the bar 45 of the trailing end clamp. To effect such mounting I provide the bar 45 with downwardly projecting headed pins 45 (Figs. 7 and 8) and I provide notches 55 in the removablebar 50 adapted to snugly embrace such pins. Likewise, I `provide upwardly extending headed pins-56 on the bar 55 and I form the bar 45 with notches 46 adapted to vreceive such pins. The bar has notches 5"|` to clearthe anchorages of the Springs 70- `Fig.48 shows the 'position of the supporting bar 4D .and the removable pin bar 50 as the latter is about to be put in place by a movement toward the right, Aand thus come intofthe position shown in Fig. 7, where the Ypin bar is definitely supported by the supporting bar.

VTe lock the pin bar in its mounted position, I provide a pair vof leaf springs 6U anchored adjacent one end to the supporting bar 40 as by rivets 6|, Figs. l, 6 and 9. 'Each spring 6|! adjacent its free end carries a downwardly extending pin V62, which may be riveted to the spring, and which extends through an opening in the supporting bar and Vbeyond it so that it is adapted to come into an opening 58 in the pin bar 50. This prevents the bar shifting in or out, so that it is definitely locked to the supporting bar. The freejendof the springt!) is preferably bent upward slightly as at 64, Fig. 6, so that it may be readily lifted by ones -nger nail.

When the bar 50 is mounted on the supporting bar 40 a clamp such as shown in Fig. 4 results, having the downwardly projecting pins 5| adapted to pass through the master sheet into the spaces between the teeth 3E) on the anvil. The prongs 5| are sharpened asshown -in Figs. 4 and 5; accordingly, in the case of an imperforate sheet they may act to perforate the sheet and thus'form an effectivem attachment thereto, ior

if the sheet is already provided with correspondi ingly spaced perforations the pins may readily occupy such perforations.

The supporting bar 40 is preferably curled inwardly along its intermediate portion, as shown at 48, in Figs. 1 and 5. This inwardly projecting edge making a convenient grippingledge whereby the operator by inserting his fingers beneath the ledge may readily pull the clamp upwardly and outwardly against the action of the tension springs 10 into the position shown in Fig. 4. Then if such clamp is swung downwardly toward the anvil 3|, the prongs or pins 5| pass through the perforated sheet into the transverse spaces between the teeth 3i). Accordingly, the master sheet is effectively clamped between the pin bar and the anvil, while the springs l0 are effective to apply inward pull to the clamp .and thus 4maintain the master sheet under tension.

I-f the master sheet is-imperforate and adapted to be perforated by the prongs 5|1 or if it has a row of perforations spaced according to the pins 5|, then the clampas stated, may be used with such sheet. However, sometimes the master sheet has a row ofperforations spaced differently from the pins 5| on the pin bar 5i) and ac f cordingly in that case -Iureplace the pin bar 5|) by a corresponding bar 50a., Fig. 10, anda row of pins 52 differently placed from the pins 5|. This bar is equippedwith headed pins 55a and edge notches 55aA and 51a and holes 58a in the same4 manner as the .pin bar 50 and thus may be readily mounted in place of that bar. l

When it is desired to change the trailing end clamp from the condition -first described, where it carries the pinabar 55, it is only necessary for the operator to lift the two springs 640 to Afree the pins 62 from the pin bar and slide out the pin bar :and slide in another pin bar, such as the bar 50a of Fig. 1.0, the returning pin 62 on the springs then holding that bar rigid with the supporting bar 4|).V

The pins on the bar 50a are shown in lFigs. -10 y as positioned with reference to the openings onth'e scallgped and perforated master sheet -B of Fig. 9. The .pins 52 therefore are spaced .in accordance with the `spacing of the hooks 29 on the leading end clamp. n l

I have arrangedthe comb comprising the teeth 30 of the anvil so that the spaces between these teeth will be available for .pins 5|., spaced as shown iin-Figi.Y -2, or .pins 52, spaced-as shownin Fig. l0. AIn effecting -this spacing, I .position the teeth nearly equally spaced but in certain regions omit a tongue altogether as shown in Fig. l. Notwithstanding the omissiom the toothed comb of Fig. `1 cooperates effectively with the v continuous closely spaced pins of Fig.' 2, most ofV these pins entering a lsingle narrow opening between adjacent tongues but occasionally two pins entering a single wider opening. lNow when the pin bar of Fig. l0 is used tthe pins 52 thereof will come in alternate -spacesv between the teeth of the comb. Hence the'same -comb is available for both pin bars.

It will -be vseen that by lthe simple arrangement of interchangeable :pin bars with an anvil combl common thereto, vand 'the provision 'of a leading end clamp adapted to hold `both imperforate Aand perforated sheets, I am enabled to take care fon a -single drum of master sheets having widely different end formations, namely, imperforate en'ds, straightened perforated ends, and scal- Y loped perforated ends, 'and the. drum thus equipped can accordingly take care of these differently formed sheets, such as are new on the market.

I claim:

1. The combination of a drum having a gap, a pivotally mounted supporting bar therein., a pin bar having aA row of projecting pins, headed pins on one of said bars and notches to receive them on the other bar, whereby the pin bar may be mounted on the supporting bar by sliding action, an anvil on the drum, and spring means acting on the supporting bar to press the pin bar toward the anvil.

2. The combination of a drum having a gap, a movable supporting bar within the gap extending lengthwise of the drum, a removable pin bar, upwardly projecting headed pins on the pin bar, notches on the supporting bar registering therewith, downwardly projecting pins on the supporting bar and notches on the pin bar registering therewith, whereby the pin bar may be slidably mounted on the underside of the supporting bar, and an anvil on the drum having openings to receive the pins.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 775,078 Dick Nov. 15, 1904 786,633 Dick Apr. 4, 1905 833,713 Gesteiner Oct. 16, 1906 883,523 Harris Mar. 3, 1908 1,996,583 Marcher Apr. 2, 1935 2,356,016 Curtis May 30, 1944 2,381,461 Morse Aug. 7, 1945 2,383,193 Stempel Oct. 30, 1945 

